Imaging Guided Patient Selection for Interventional Revascularization Therapy

Inclusion Criteria: * From 18 to 85 years of age. * Evidence of proximal anterior circulation large vessel occlusion (TIMI /TICI 0-1) (Tables 2A \& B). Target vessel occlusion may include the supra-clinoid segment of the ICA through the M1 segment of the MCA. * Presented with symptoms consistent with acute ischemic stroke within 8 hours of symptom onset. Patients who presented within 3 hours must be ineligible or refractory to IV rtPA therapy. * At time of enrollment, neurological deficit resulting in an NIH Stroke Scale (NIHSS) score of 10 or greater. * Core infarct volume assessed by CTP, CTA or DWI scans within 60 minutes to arterial puncture. * Signed informed consent. Exclusion Criteria: * History of stroke in the past 3 months. * Vessel tortuosity too difficult to allow endovascular access. * Pre-existing neurological or psychiatric disease that could confound the study results such as a pre-stroke mRS score of 1 or greater. * Known severe allergy to contrast media. * Uncontrolled hypertension (defined as systolic blood pressure \> 185 mmHg or diastolic blood pressure \> 110 mmHg). * Noncontrast CT evidence of the following conditions before enrollment: * Significant mass effect with midline shift; * Evidence of intracranial hemorrhage. * Angiographic evidence of an arterial stenosis proximal to the occlusion that could prevent thrombus removal. * Angiographic evidence of preexisting arterial injury. * Life expectancy less than 90 days. * Participation in anothe…